The notion that the world’s people share a set of values that only a madman could possibly reject is exactly backwards. Clearly, the whole world does not share our commitment to republican governance, let alone embrace our values of free speech, religious pluralism, and ordered liberty. To the contrary, large numbers of people reject democracy outright, relying instead on Mao’s maxim that power derives from the barrel of a gun.

When Thomas Jefferson wrote, in 1776, that human beings are endowed by their Creator with certain unalienable rights, that among these are the rights to “life, liberty, and the pursuit of happiness,” he articulated a universal truth — but this truth was not universally accepted by the world. To the contrary, the Founding Fathers’s ideas about liberty and republican governance were, to 18th century minds, nothing short of radical.

Because our unique democratic ideals subsequently gained traction in far corners of the earth, we have, perhaps, been lulled into a sense of complacency — into a sense that our values are, indeed, universal.

But terrorist attacks, like the ones that occurred in Paris on Friday, prove that they are not.

Significantly, the people who committed Friday’s attack are not crazed madmen; they are not outliers who reject some supposed set of universal values. Rather, they are foot soldiers in a radical Islamist holy war against Western values; they are participants in an international conspiracy to defeat democratic principles; they are crusaders, dedicated to the proposition that those who refuse to submit to their will must die.

Those who view the perpetrators of such attacks as individual criminals to be apprehended, rather than as enemies of Western values who must be defeated, underestimate the enormity of the threat — and they render us powerless to stop it.

The immediate reaction of the French government to the terrorist massacre in Paris was to close the borders. This reactionary impulse was reinforced by revelations that one of the perpetrators had gotten into the country claiming to be a Syrian refugee. But what will be the reaction when it becomes clear, as it inevitably will, that others involved in the terror plot were raised in the West?

Closing the borders doesn’t help if the terrorist threat already lies within. And too often (as in the case of the Boston Marathon bombers, for example) the terrorists are homegrown.

Too often, terrorists and their sympathizers were raised in Western nations that encourage young people to think of themselves, not as fortunate to live in a land of freedom and opportunity, but as victims of the racism and intolerance of the dominant culture.

Too often, the terrorists live and work in Western countries that not only tolerate, but subsidize, entire industries based on perceived ethnic grievances.

Too often the terrorists are educated in Western democracies too embarrassed of their history to teach it, too ashamed of their culture to celebrate it, and too cowardly to suggest, much less insist, that those who seek sanctuary on their shores become fully assimilated.

Shame on those who assume, naively, that our values are shared by all. Shame on those who fail to understand that their ideology of multiculturalism is incompatible with their naive notion of “universal values.” Shame on those who have turned Western values into a license for trivial pursuits of selfish satisfaction and who have allowed our culture to breed hatred among the lost.

Those who push the ideology of multiculturalism at the expense of assimilation share blame for the blood on the streets of Paris — just as they will share blame for the anti-immigrant backlash that will inevitably follow from this horrific attack. It is they who have inadvertently created the ideological incubator in which ancient hatreds continue to flourish.